The article results from a qualitative research on the perception of health of the Guarany Mbyá ethnic group held in 3 villages in the South of Brazil. The cultural characteristics of the group were surveyed in the literature, observed in fieldwork and confirmed in the 20 open interviews conducted with community members and health professionals from the National Health Foundation (FUNASA), responsible for the basic assistance to the villages. The results show that the Mbyá consider the cultural shock with the surrounding society the main factor of illness, emphasizing the importance of preserving and enhancing their traditional way of living for maintaining the health of individuals and communities. The data allow to associate their health representations to the land and social justice problems experienced by the groups. They point to the importance of improving the training of the technical health staff, specifically related to the understanding of the inter-ethnic differences between the Mbyá and Western culture to ensure the effectiveness of treatments and programs. The analyses also highlights positive and negative aspects of the operationalization of health care in the villages and in the final considerations are given suggestions aiming its improvement.